Surgical stapling apparatus

ABSTRACT

A surgical stapling apparatus having a housing with an actuator and an elongated member extending from the housing. An end effector is disposed on one end of the elongated member. The end effector houses a plurality of fasteners that are operatively coupled to a plurality of pusher members. An actuation mechanism is operatively coupled to the actuator; the actuation mechanism includes a longitudinally translatable drive member and an actuation sled. The actuation sled is configured for engaging the plurality of pusher members. A pressure responsive element is also disposed in one of the jaws. The pressure responsive element communicates a signal to a controller. The signal is representative of pressure applied to the pressure responsive element. The controller is configured to activate a feedback response.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Continuation application which claims the benefit of and priority to U.S. patent application Ser. No. 12/796,270, filed on Jun. 8, 2010, which claims the benefit of and priority to U.S. Provisional Application Ser. No. 61/232,826, filed on Aug. 11, 2009, the entire contents of each of which are incorporated herein by reference.

BACKGROUND

1. Technical Field

The present disclosure relates to surgical stapling apparatuses that are capable of applying lines of fasteners to tissue while cutting the tissue between those fastener lines and, more particularly, to improvements relating to fastener deployment and formation.

2. Background of Related Art

Endoscopic and laparoscopic surgical apparatuses are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. The use of laparoscopic and endoscopic surgical procedures has been relatively popular and has provided additional incentive to develop the procedures further. In laparoscopic procedures, surgery is performed in the interior of the abdomen through a small incision. Similarly, in endoscopic procedures, surgery is performed in any hollow viscus of the body through narrow endoscopic tubes inserted through small entrance wounds in the skin.

Laparoscopic and endoscopic procedures generally require that the surgical region be insufflated. Accordingly, any instrumentation inserted into the body must be sealed to ensure that gases do not enter or exit the body through the incision. Moreover, laparoscopic and endoscopic procedures often require the surgeon to act on organs, tissues and/or vessels far removed from the incision. Thus, apparatuses used in such procedures are typically long and narrow while being functionally controllable from a proximal end of the apparatus.

Significant development has gone into a range of endoscopic surgical apparatuses that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).

Known surgical stapling apparatuses include an end effector that makes a longitudinal incision in tissue and subsequently applies lines of fasteners on opposing sides of the incision. The end effector includes a pair of cooperating jaws that, if the apparatus is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the jaws receives a fastener cartridge having at least two laterally spaced rows of fasteners. The other jaw defines an anvil having fastener-forming pockets aligned with the rows of fasteners in the cartridge. The apparatus includes a plurality of reciprocating wedges or cam bars which, when driven distally, pass through openings in the fastener cartridge and engage drivers supporting the fasteners to effect the firing of the fasteners toward the anvil.

Small videoscopes of various types (e.g., endoscopes) are relied upon to monitor proper positioning and operation of the surgical stapling apparatus. While effective to a degree, it is desirable to have improved monitoring of operation of the surgical stapling apparatus, especially if such monitoring enables improved fastener deployment and formation quality performed by the surgical stapling apparatus. When utilizing stapling devices containing multiple fasteners in each cartridge load, it is also beneficial to determine which fasteners are being deployed and formed properly. It is important to understand where formation or progression problems lie because there are various clearance and deformation issues that can influence proper fastener deployment and formation.

Consequently, a continuing need exists for an improved surgical stapling and severing apparatus that incorporates fastener deployment and formation pressure monitoring capabilities to assure the mechanical and hemostatic integrity of a surgical stapling device.

SUMMARY

In accordance with the present disclosure, a surgical stapling apparatus is disclosed. The surgical stapling apparatus has a housing having an actuator; an elongated member extending from the housing; an end effector disposed on one end of the elongated member, the end effector including first and second jaws; a plurality of fasteners disposed in the end effector; a plurality of pusher members located in the end effector, each pusher member in the plurality of pusher members operatively coupled to a number of fasteners; an actuation mechanism operatively coupled to the actuator, the actuation mechanism including a longitudinally translatable drive member and an actuation sled coupled thereto, the actuation sled configured for engaging the plurality of pusher members; and a pressure responsive element disposed in one of the jaws, the pressure responsive element communicating a signal to a controller coupled to the surgical stapling apparatus, the signal representative of pressure applied to the pressure responsive element.

In one embodiment, interaction between the actuation sled and the pusher members applies pressure to the pressure responsive element. The pressure responsive element includes staggered pressure sensors in a circuit. The circuit, in some manifestations is a printed pressure circuit or a flexible circuit disposed on the surface of a channel positioned in one of the jaws.

In another embodiment, the surgical stapling apparatus can include a circuit that is disposed on the external surface of at least one of the jaws. In this version, the stapling apparatus also includes a beam, the beam disposed on the external surface of at least one of the jaws and seated in a groove disposed within at least one of the jaws so that the beam can be configured to translate along the groove. The beam may be an I-beam or an E-beam.

The circuit can have a laminate layer on the circuit and may even have a lubricant coating on the laminate layer. The signal communicated to the controller will from time to time be read by the controller as irregular. In such a case, the controller will activate a feedback response such as an error code, warning, or it may even stop fastener deployment altogether. It is contemplated that the pressure responsive element communicates the signal to the controller through by any of the following: voltage, resistance, impedance, electromagnetism, radio frequency, current, inductance, capacitance, infrared, optics, or any combination thereof.

Another embodiment envisions a knife configured to translate through the jaw to cut tissue. However, upon certain predetermined irregularities, the controller can prevent the knife from cutting, should those irregularities fall within those predetermined conditions. An encoder is configured to recognize irregular component positions relative to the pressure applied and send a signal to the controller. The encoder may be configured to recognize irregular positions of various components including the actuation mechanism, the knife, the actuator, the actuation sled, the pusher member, the first jaw, the second jaw, or even various combinations thereof. These encoders can be linear or rotational.

Certain embodiments contemplate the circuit including a cartridge identifying feature. Other embodiments can have controller configured to set positional limitations and run mode for a particular load or fastener type. Still further, one of the jaws may be configured and dimensioned to house a non-linear cartridge.

In other embodiments, the controller includes an end user feedback communication feature. The end user feedback communication feature is configured to communicate the feedback to an end user through percipient signals such as audible, visual, tactile, or any combination thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which:

FIG. 1A is a perspective view of a powered surgical stapling apparatus;

FIG. 1B is a perspective view of a manual surgical stapling apparatus;

FIG. 1C is an enlarged perspective view of the end effector of a surgical stapling apparatus;

FIG. 1D is a perspective view of the end effector during a fastener applying operation as the wedge translates through the cartridge to sequentially eject the fasteners from the cartridge and drive them against one of the jaws to be formed thereby;

FIG. 2 is a schematic view of a surgical stapling system in accordance with the present disclosure;

FIG. 3A is a side cross-sectional view of a portion of the end effector of the surgical stapling apparatus' of FIGS. 1A and 1B;

FIG. 3B is a side cross-sectional view of a portion of the end effector of the surgical stapling apparatus' of FIGS. 1A and 1B with a cartridge wall removed for clarity;

FIG. 4A is a side elevational view of the surgical stapling apparatus of FIG. 1B with the housing sectioned to illustrate the actuation mechanism when the actuator is manipulated through one an actuation stroke to apply a portion of the fasteners from the cartridge to tissue;

FIG. 4B is a perspective view in partial cross-section of the surgical stapling apparatus of FIG. 4A in accordance with the present disclosure;

FIG. 5 is a plot of the pressure applied to form staples versus time;

FIG. 6 is a perspective view of the interior channel of the cartridge with a printed pressure circuit disposed therein;

FIG. 7 is a perspective view of a removable end effector of FIGS. 1A and 1B illustrating a knife slot in one of the jaws;

FIG. 8A is a perspective view of the end effector of FIG. 7 with the anvil cover removed for clarity showing a pressure circuit;

FIG. 8B is an enlarged perspective view of the embodiment disclosed in FIG. 8A;

FIG. 9 is a schematic view of the end user feedback communication feature according to one embodiment of the present disclosure;

FIG. 10 is a schematic view of the cartridge identifying feature according to one embodiment of the present disclosure; and

FIG. 11 is a schematic of the encoder feature according to one embodiment of the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

Embodiments of the presently disclosed surgical stapling apparatus will now be described in detail with reference to the drawings, in which like reference numerals designate identical or corresponding elements in each of the several views.

As shown in the drawings and as described throughout the following description, and as is traditional when referring to relative positioning on an object, the term “proximal” refers to the end of the apparatus that is closer to the user and the term “distal” refers to the end of the apparatus that is further from the user. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure in unnecessary detail.

FIG. 1A illustrates a powered surgical stapling apparatus shown generally as 100. FIG. 1B illustrates a manual surgical stapling apparatus shown generally as 200. Briefly, the surgical stapling apparatus 100, 200 includes a housing 102 having an actuator 136, an elongated member 104 extending from the housing 102, and an end effector 106 disposed on one end of the elongated member 104. From FIGS. 1C-1D, the end effector 106 includes first and second jaws 108, 110, a plurality of fasteners 114 disposed in the end effector 106 and a plurality of pusher members 130 located in the end effector 106. Each pusher member 130 in the plurality of pusher members 130 is operatively coupled to a number of fasteners 114. As seen in FIGS. 3A-4B, the surgical stapling apparatus 100, 200 includes an actuation mechanism 138 operatively coupled to the actuator 136. The actuation mechanism 138 includes a longitudinally translatable drive member 140 and an actuation sled 132 coupled thereto. The actuation sled 132 is configured for engaging the plurality of pusher members 130.

In accordance with one embodiment of the present disclosure, FIG. 2 diagrams a surgical stapling system having a surgical stapling apparatus 100, 200, the surgical stapling apparatus 100, 200 having a pressure responsive element 150 and a controller 120. It is envisioned that the pressure responsive element is disposed in one of the jaws 108, 110 (FIGS. 3A-3B and 8A-8B). The pressure responsive element 150 can communicate a pressure signal 152 (not shown) to the controller 120 coupled to the surgical stapling apparatus 100, 200. The controller 120 is a microcontroller or an analog circuit which enables control, positioning, status, and fastener 114 quality feedback. The pressure signal 152 is representative of pressure applied to the pressure responsive element 150. It is envisioned that this embodiment may include a knife 164 or be knifeless, the knife 164 slidably translatable through a knife slot 174 (FIG. 1C).

Referring to FIG. 5, applied pressure may be measured in the form of waveform pulsations as seen in the time versus applied pressure graph. For example, a normal sample might read in accordance with the graph covering the time period from 0-t1. If the waveform pulsations indicate a low (t2-t3) or high (t1-t2) pressure during a certain sampling, this could be an indication that the fasteners 114 are not being properly deployed or formed due to improper applied pressure distribution necessary for proper fastener 114 deployment or formation. Alternatively, if the waveform is not a shape that has been correlated with successful test waveforms (t3-t4), an error code or feedback is initiated by the controller 120 to stop deployment or formation progression. This gives the end user the ability to properly understand the performance irregularity before proceeding or backing out.

As seen in FIGS. 3A-3B, the first jaw 108 includes a cartridge channel 128 for receiving a cartridge 112. The cartridge 112 includes a plurality of fasteners 114 disposed therein. Typically, fasteners 114 are in the form of a plurality of surgical staples. The cartridge 112 houses the fasteners 114 in a plurality of linear rows, which are operatively coupled to the pusher members 130.

Referring now to FIG. 6, the pressure responsive element 150 of one manifestation includes a circuit 124 wherein at least one lead 154 connects at least one pressure sensor 126. It is also contemplated that a plurality of pressure sensors 126 are disposed on the surgical stapling apparatus 100, 200. In one instance, a lead 154 extends across a plurality of pressure sensors 126 in linear progression along the longitudinal axis, wherein at least one pressure sensor 126 corresponds to each fastener 114 or pusher member 130. Each linear row of fasteners 114 and/or pusher members 130 is connected by at least one lead 154 extending along the linear row and along the longitudinal axis of the circuit 124. The circuit 124 is a flexible or a printed pressure circuit 124.

In this embodiment, the circuit 124 is adhered to the top (working) surface of the cartridge channel 128 so that the circuit 124 can interact with the actuation sled 132 that translates therethrough. In other words, the circuit 124 is disposed within the cartridge channel 128 to matingly engage the actuation sled 132 as the actuation sled 132 translates through the cartridge channel 128 (FIGS. 3A-3B).

FIGS. 7-8B show another embodiment of the surgical stapling apparatus 100, 200. As seen in FIGS. 8A-8B, the surgical stapling apparatus 100, 200 includes a pressure responsive element 150 that includes a circuit 124 and is disposed on the external surface of at least one of the jaws 108, 110. Preferably, the circuit 124 is disposed on the external surface of the second jaw 110. This embodiment includes a beam 162. The beam 162 is disposed on the external surface of at least one of the jaws 108, 110. Preferably, the beam 162 is disposed on the external surface of the second jaw 110. It is also contemplated that the beam 162 is slidably seated in a groove 116 disposed within at least one of the jaws 108, 110 and connected to the actuation sled 132 (FIGS. 8A and 8B). The beam 162 is slidably seated in a groove 116 disposed within the second jaw 110. The beam 162 is configured to translate along the groove 116. The beam is an I-beam or an E-beam. This circuit 112 is envisioned to be very thin with respect to the surgical stapling apparatus 100, 200, having dimensions at least geometrically thin enough as to not compromise or greatly impact the overall cartridge 112 size or function.

In some manifestations, the pressure sensors 126 are staggered (FIGS. 3B, 6, 8A, 8B). The circuit 124 in one arrangement is staggered and optimized so that detailed information can be obtained for each fastener 114 or group of fasteners 114 formed by their associated pusher member 130. By having the pressure sensors 126 staggered from the proximal to distal positions relative to the fasteners 114 within the surgical stapling apparatus 100, 200, the surgical stapling apparatus 100, 200 can be configured to determine deployment timing and completion of each fastener 114. This is valuable for controlling the surgical stapling apparatus 100, 200 with a controller 120 to verify limits with each specific cartridge 112 for clamping, distal stop, or home position. The controller 120 may have an analog or a microelectronic circuit.

As fastener 114 progression unfolds, the pressure responsive element 150 communicates a pressure signal 152 to the controller 120 through at least one communication means selected from the group comprising voltage, resistance, impedance, electromagnetism, radio frequency, current, inductance, capacitance, infrared, and optics. In operation, the pressure responsive element 150 tracks the applied pressure as the fasteners 114 are deployed and formed in progression (FIG. 5). In some cases, the applied pressure can be tracked in the form of waveform pulsations. When the controller 120 recognizes irregular pressure patterns represented by the pressure signal 152 communicated from the pressure responsive element 150, the controller 120 correspondingly registers an error and may be configured to emit an error code, emit a warning, stop fastener 114 formations, or even stop fastener 114 deployments.

The pressure responsive element 150 may also be configured for both linear and non-linear cartridge 112 configurations. It is envisioned that at least one of the jaws 108, 110, preferably the first jaw 108, includes a non-linear cartridge. In other words, the pressure responsive element 150 can be used for linear cartridge 112 surgical stapling apparatuses 100, 200 or non-linear cartridge 112 surgical stapling apparatuses 100, 200 including curved, circular, or any other geometrically-shaped cartridge 112 required to assess fastener quality or progression status.

Often, the surgical stapling apparatus 100, 200 can include a knife 164. In one manifestation of the present disclosure, the surgical stapling apparatus 100, 200 is configured and dimensioned such that the controller 120 prevents the knife 164 from cutting. In other words, the controller 120 includes an encoder 166, i.e., a knife cutting prevention feature. As seen in FIG. 11, one configuration contemplates the encoder 166 configured to recognize irregular behaviour of the surgical stapling apparatus 100, 200. In some instances, the encoder 166 is configured and dimensioned to recognize component positions relative to the pressure applied. The components of which are selected from the group comprising the actuation mechanism 138, knife 164, actuator 136, actuation sled 132, pusher member 130, first jaw 108, and second jaw 110, or any combination thereof. The encoder 166 can be rotational, or even linear.

Referring to FIG. 9, the controller 120, in some manifestations, includes an end user feedback communication feature 170. The end user feedback communication feature 170 is configured to communicate feedback to an end user after receiving and deciphering a signal 152, 191 through at least one means selected from the group comprising audible (bells, speech, buzzers, beeps, etc.), visual (lights, LED's, LCD, or electroluminescent screens of varying colors, text, and/or symbols), and tactile (vibratory). For example, the feedback may be configured to indicate the successful or unsuccessful completion of a task such as initiation of fastener deployment progression, completion of fastener deployment and formation, individual fastener deployment, individual fastener formation, or other similar tasks recognized by a person of ordinary skill in the art.

To protect the circuit 124 from tearing or abrasion and to attain accurate, repeatable feedback, a thin, hard surface material such as Kapton® polyimide film or a foil of titanium or steel alloy or a flash coated nickel, chrome or nitride coating can be laminated onto the top layer of the circuit 124, defining a laminate 158. Furthermore, a lubricant coating 160 may also be applied to the laminate layer. The lubricant coating 160 is any low friction plastic, grease, PTFE blended material, or any other comparable lubricant. The lubricant 160 is beneficial for achieving a quality output pressure signal 152 and for improving the robustness of working components.

As seen in FIG. 10, the surgical stapling apparatus 100, 200 may have a circuit 124 including a cartridge identifying feature 168. In particular, the pressure responsive element 150 includes at least one circuit 124, wherein each circuit 124 has a specific electrical range or value of resistance, inductance, or impedance that can be read by the controller 120 to determine the exact type of cartridge 112 or end effector 106 loaded for identification. With this feature, the surgical stapling apparatus 100, 200 includes a controller 120 configured to set cartridge 112 or fastener 114 specific positional limitations and/or run mode.

In operation, when an end user (not shown) actuates the actuator 136, the actuating mechanism 138 causes the actuation sled 132 to interact with the pusher members 130 (FIG. 4A). In certain variations, the actuator 136 includes separate actuating features for actuating the actuation sled 132 and the first and second jaws 108, 110. For example, an actuation sled actuator 136 a is used to remotely actuate the actuation sled 132, and a jaw actuator 136 b is used to actuate first and second jaws 108, 110. Alternatively, a single actuator 136 is used to actuate both the actuation sled 132 and the jaws 108, 110. In another example, separate actuators 136 are connected to the individual first and second jaws 108, 110.

Upon actuation, the actuation sled 132 wedges the pusher members 130 upwards, forcing the fasteners 114 up into the opposing second jaw 110 surface, and in particular, into fastener-forming pockets 156 (FIG. 1D). From FIG. 1D, in its initial configuration the fastener 114 is shaped in a substantially U-shaped configuration. In its fully formed configuration, the faster 114 is shaped in a substantially B-shaped configuration. In the process of transforming the fastener 114 from the first configuration to the second configuration, the second jaw 110 acts as an anvil and correspondingly compresses the fastener 114 into its second configuration B-shape as the fastener prongs 114 a, 114 b engage the fastener-forming pockets 156. This resulting pressure applied to the pressure responsive element 150 is therefore a result of the interaction between the actuation sled 132 and the pusher members 130.

In embodiments where the pressure responsive element 150 includes a circuit 112 disposed within the cartridge channel 128, the downward force of the second jaw 110 onto the upwardly driving fastener 114, pusher member 130, and actuation sled 132 combination consequently causes reaction forces to pass through fasteners 114, pusher member 130, and actuation sled 132 combination in the opposing downward direction and onto the circuit 112 and any pressure sensors 126, which correspondingly register the applied pressure. The pressure responsive element 150 than communicates a pressure signal 152 to the controller 120, where the pressure signal 152 is representative of the pressure applied to the pressure responsive element 152. The controller 120 receives the pressure signal 152 and selectively emits a response or feedback based on the pressure signal 152.

In embodiments where the pressure responsive element 150 includes a circuit 112 disposed on the external surface of one of the jaws 108, 110. For example, when the circuit 112 is disposed on the external surface of the second jaw 110, applied pressure is displaced from the beam 162, which is connected to the actuation sled 132, onto the circuit 112 as both the beam 162 and the actuation sled 132 translate longitudinally along the first and second jaws 108, 110. In other words, as the actuation sled 132 translates and engages the pusher members 130, the pusher members 130 drive fasteners 114 up into the second jaw 110 and fastener-forming pockets 156. This consequently causes downward reaction forces to be displaced to the beam 162 onto the circuit 112 as the actuation sled 132 pulls down the beam 162 from the resultant downward reaction forces from the fastener-forming pockets 156 pass through the fasteners 114 and pusher members 130 onto the actuation sled 132. The pressure sensors 126 correspondingly register the applied pressure. The pressure responsive element 150 than communicates a pressure signal 152 to the controller 120, where the pressure signal 152 is representative of the pressure applied to the pressure responsive element 152. The controller 120 receives the pressure signal 152 and selectively emits a response or feedback based on the pressure signal 152.

In embodiments that include an encoder 166, the encoder 166 is configured to recognize the irregular behaviour of a component of the surgical stapling apparatus 100, 200 the components of which can be selected from the group comprising the actuation mechanism 138, knife 164, actuator 136, actuation sled 132, pusher member 130, first jaw 108, and second jaw 110. In one example where the encoder 166 is configured to monitor the positions of the knife 164, and where the encoder 166 recognizes an irregular position of the knife 164, the encoder 166 communicates the irregularity to the controller 120 via an encoder signal 191, the signal either regular 191 a or irregular 191 b. Upon receiving an irregular signal 191 b, the controller 120 registers an error code, and in some instances, is configured to prevent cutting without fastening.

The encoder 166 communicates the encoder signal 191 to the controller 120 through at least one means selected from the group comprising voltage, resistance, impedance, electromagnetism, radio frequency, current, inductance, capacitance, infrared, and optics. It is also envisioned that the controller 120 is configured and dimensioned to receive an encoder signal 191 from the pressure responsive element 150 and to determine fastener 114 deployment and formation disparities with respect to the component behaviour, e.g., the knife's 164 irregular positioning. The controller 120 is also configured and dimensioned to initiate an error code or modify fastener 114 deployment settings.

While several illustrative embodiments of the disclosure have been shown in the drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of preferred embodiments. Thus the scope of the embodiments should be determined by the appended claims and their legal equivalents, rather than by the examples given. 

What is claimed is:
 1. An end effector for performing a surgical function, the end effector comprising: a cartridge member defining a plurality of fastener retaining slots dimensioned to support a plurality of fasteners; an anvil member defining a plurality of fastener forming pockets dimensioned to form the plurality of fasteners upon a firing of the end effector; a pressure responsive element supported on a top surface of the anvil member opposite a tissue contacting surface of the anvil member and being configured to communicate a signal representative of pressure applied to the pressure responsive element upon the firing of the end effector; and a beam supported between the anvil member and the cartridge member, the beam being engageable with the cartridge member and the anvil member to effectuate a closure of the end effector upon a distal advancement of the beam, wherein the beam engages the pressure responsive element as the beam is advanced.
 2. The end effector of claim 1, wherein the pressure responsive element includes a plurality of staggered pressure sensors.
 3. The end effector of claim 1, wherein the pressure responsive element includes a circuit.
 4. The end effector of claim 3, wherein the circuit includes a cartridge identifying feature.
 5. The end effector of claim 3, wherein the circuit includes at least one of a printed pressure circuit and a flexible circuit.
 6. The end effector of claim 3, further comprising a laminate layer on the circuit.
 7. The end effector of claim 6, further comprising a lubricant coating on the laminate layer.
 8. The end effector of claim 1, wherein the pressure responsive element is operatively coupled to a controller, the controller being configured to receive the signal.
 9. The end effector of claim 8, wherein when the signal is irregular, the controller is configured to activate at least one feedback response selected from the group comprising emitting an error code, emitting a warning, and stopping the firing of the end effector.
 10. The end effector of claim 8, further comprising a knife selectively advanceable along the anvil member and the cartridge member, wherein the controller is configured to prevent movement of the knife.
 11. The end effector of claim 8, further comprising an encoder operatively coupled to the controller, the encoder being configured to recognize signal irregularities with regard to the pressure applied.
 12. The end effector of claim 11, wherein the encoder is at least one of a rotational and a linear encoder.
 13. The end effector of claim 8, wherein the controller is configured to set positional limitations and a run mode for at least one of a particular load and a particular fastener type.
 14. The end effector of claim 1, wherein the cartridge member supports a non-linear cartridge.
 15. The end effector of claim 1, wherein the beam includes a cross member dimensioned to engage the pressure responsive element as the beam member is advanced.
 16. The end effector of claim 15, wherein the anvil member defines a slot that extends between the tissue contacting surface and the top surface of the anvil member, the beam being axially advanceable along the slot relative to a longitudinal axis defined by the anvil member, the cross member extending transverse to the longitudinal axis of the anvil member and being engageable with the top surface of the anvil member along opposed sides of the slot.
 17. A method for monitoring formation pressure of surgical fasteners during a firing of an end effector of a surgical stapling apparatus, the method comprising the steps of: forming fasteners supported in fastener retaining slots of a cartridge assembly against fastener forming pockets of an anvil member; applying pressure to a pressure responsive element supported on the anvil member in response to a formation of at least one of the fasteners; and generating a signal based upon the applied pressure to the pressure responsive element to determine the amount of pressure being applied to the pressure responsive element.
 18. The method of claim 17, further comprising the step of communicating the signal to a controller that is disposed in electrical communication with the pressure responsive element.
 19. The method of claim 18, further comprising the step of:: upon communicating an irregular signal to the controller, activating at least one feedback response selected from the group comprising emitting an error code, emitting a warning, and stopping fastener deployment.
 20. The method of claim 19, further comprising the step of: preventing movement of a knife operatively coupled to the anvil and cartridge members in response to the irregular signal being communicated to the controller. 